LESS Mixin for Multiple Transition Properties under Same duration, timing-function and delay; See https://medium.com/@mnjul/less-mixin-for-multiple-transition-properties-under-same-duration-timing-function-and-delay-15e1aa18543a

multi-transition-props.less

// Apache License: https://www.apache.org/licenses/LICENSE-2.0

// For LESS version > 3.0.0, please turn on a flag to enable inline JavaScript:
// http://lesscss.org/usage/#less-options-enable-inline-javascript-deprecated-

.uniform-transition(...) {
  transition: ~`(function(lessArgsStr){
                   var lessArgs = lessArgsStr.substr(1, lessArgsStr.length - 2).split(','); // Or use regexp
                   return lessArgs
                     .splice(1)
                     .map(function(prop){ return prop + ' ' + lessArgs[0]; })
                     .join(',');
                 })('@{arguments}')`;
}

.first-box {
  .uniform-transition(0.4s linear 0.1s, height, width);
}

.second-box {
  .uniform-transition(0.4s linear 0.1s, height);
}

.third-box {
  .uniform-transition(0.4s, height);
}